Field
The present specification generally relates to laminated glass articles and, more specifically, to laminated glass sheets or tubes having improved edges and methods for making laminated glass sheets or tubes having improved edges.
Technical Background
Glass sheets may be employed as automotive glazed glass or architectural glazed glass. Additionally, glass sheets, such as cover glasses, glass backplanes and the like, are employed in both consumer and commercial electronic devices such as LCD and LED displays, computer monitors, automated teller machines (ATMs) and the like. Some of these glass sheets may include “touch” functionality which necessitates that the glass sheet be contacted by various objects including a user's fingers and/or stylus devices and, as such, the glass must be sufficiently robust to endure regular contact without damage. Moreover, such glass sheets may also be incorporated in portable electronic devices, such as mobile telephones, personal media players, and tablet computers, automobiles, or buildings. The glass sheets incorporated in these apparatuses may be susceptible to damage during transport and/or use of the associated apparatus. Accordingly, glass sheets used in various apparatuses may require enhanced strength to be able to withstand not only routine “touch” contact from actual use, but also incidental contact and impacts which may occur when the device is being transported.
In laminated glass sheets, the surfaces of the sheet may be strengthened through compressive stresses created, for example, by a mismatch in coefficient of thermal expansion (CTE) between a core layer and clad layers of the laminated glass sheets. However, strengthening of the surfaces through compressive stress will generally create a high tensile stress in the core layer, which may be exposed when the glass sheet is cut. If the exposed glass core layer has a defect or is subjected to a damage event, failure or breakage of the glass sheet may occur.
Accordingly, a need exists for strengthening exposed edges of laminated glass sheets.